Centrifugal machine test device for simulating foundation pit support dismounting by utilizing laser irradiation

Abstract

The utility model discloses a centrifugal machine test device for simulating foundation pit support dismantling by utilizing laser irradiation, which comprises a model box, the upper part of the model box is open, a test soil sample is arranged in the model box, and an underground diaphragm wall model is pre-buried in the test soil sample; the same positions of the two sides of the diaphragm wall model are each provided with a row of strain gauges which are sequentially arranged from top to bottom, the diaphragm wall model extends in the width direction of the whole inner opening of the model box, the bottom of the diaphragm wall model is suspended on a bottom plate of the model box, and a foundation pit model is formed between the diaphragm wall model and the left side wall, the front side wall and the rear side wall of the model box. The bottom of the foundation pit model is formed by a test soil sample, a horizontal supporting rod made of aluminum alloy is arranged between the diaphragm wall model and the left side wall of the model box, a laser emitting device and a camera are installed on the top of the model box, and the light emitting direction of the laser emitting device is perpendicular to the horizontal supporting rod. The device can accurately and efficiently simulate support dismantling of the foundation pit, and disturbance to surrounding soil is small.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering centrifuge model tests, in particular to a centrifuge test device which utilizes laser irradiation to simulate the dismantling of foundation pit supports. Background Art

[0002] Geotechnical centrifuges use different accelerations to generate the stress-strain state of prototype foundation pits with smaller-sized models. By observing the deformation state and failure process of the model foundation pit retaining structure and the surrounding soil, it provides an effective means for in-depth research on the characteristics of foundation pit engineering under complex conditions. However, there are two main problems in the centrifuge tests of foundation pit engineering currently carried out. First, most of them are foundation pit excavation model tests, and there is little research on the support removal stage. In fact, during the construction of underground structures and the corresponding support removal stages, the impact on the ground-connected wall and soil cannot be ignored, otherwise the displacement and deformation control effect in the excavation stage will be greatly reduced. Second, in the centrifuge test, the support structure is often installed on the ground-connected wall model. Removing the support is not only inefficient, but more importantly, it will cause a large disturbance to the ground-connected wall model and the surrounding soil, which may lead to test failure. Therefore, it is necessary to carry out accurate and efficient foundation pit support removal centrifuge tests to study the stress and deformation characteristics of foundation pit engineering under complex conditions. Utility Model Content

[0003] The utility model provides a centrifuge test device for simulating foundation pit support removal by laser irradiation to solve the technical problems existing in the known technology, which can accurately and efficiently simulate the foundation pit support removal with little disturbance to the surrounding soil.

[0004] The utility model adopts the following technical scheme to solve the technical problems existing in the known technology: a centrifuge test device for simulating the dismantling of supports by laser irradiation, comprising a model box, the upper part of the model box is open, a test soil sample is arranged in the model box, a ground-connected wall model is pre-buried in the test soil sample, a row of strain gauges arranged in sequence from top to bottom are respectively arranged at the same position on both sides of the ground-connected wall model, the ground-connected wall model extends along the entire inner opening width of the model box, and the bottom is suspended above the bottom plate of the model box, a foundation pit model is formed between the ground-connected wall model and the left side wall, front side wall and rear side wall of the model box, the bottom of the foundation pit model is formed by the test soil sample, a horizontal support rod made of aluminum alloy is arranged between the ground-connected wall model and the left side wall of the model box, a laser emitting device and a camera are installed on the top of the model box, and the light emitting direction of the laser emitting device is perpendicular to the horizontal support rod.

[0005] The left end of the horizontal support rod is pressed into the limiting groove, and the right end is locked on the ground-connected wall model by a nut. The limiting groove is arranged on the inner side of the left side wall of the model box.

[0006] The advantages and positive effects of the utility model are: the horizontal support rod is irradiated with laser to simulate the dismantling of the foundation pit, which has little disturbance on the test soil sample, can accurately and efficiently simulate the dismantling of the foundation pit, and can be suitable for more complex foundation pit model tests. In addition, the utility model is easy to install and can be recycled repeatedly, which can improve the test efficiency. The use of low-melting-point aluminum alloy not only reduces the energy required for melting but also is non-toxic and harmless. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of the structure of the utility model;

[0008] Figure 2 It is the front view of the utility model;

[0009] Figure 3 It is a top view of the utility model;

[0010] Figure 4 It is a side view of the utility model.

[0011] Figure 5 It is a schematic diagram of the fixed connection between the horizontal support rod and the ground-connected wall model of the utility model.

[0012] In the figure: 1. model box; 2. ground-connected wall model; 3. horizontal support rod; 4. laser emitting device; 5. camera; 6. strain gauge; 7. test soil sample; 8. nut. DETAILED DESCRIPTION

[0013] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0014] See also Figure 1 to Figure 5A centrifuge test device for simulating foundation pit dismantling by laser irradiation comprises a model box 1, the upper part of the model box 1 is open, a test soil sample 7 is arranged in the model box 1, a ground-connected wall model 2 is pre-buried in the test soil sample 7, a row of strain gauges 6 arranged from top to bottom are arranged at the same position on both sides of the ground-connected wall model 2, the ground-connected wall model 2 extends along the entire inner opening width of the model box 1, and the bottom is suspended above the bottom plate of the model box 1, a foundation pit model is formed between the ground-connected wall model 2 and the left side wall, front side wall and rear side wall of the model box 1, the bottom of the foundation pit model is formed by the test soil sample 7, a horizontal support rod 3 made of aluminum alloy is arranged between the ground-connected wall model 2 and the left side wall of the model box 1, a laser emitting device 4 and a camera 5 are installed on the top of the model box 1, the light emitting direction of the laser emitting device 4 is perpendicular to the horizontal support rod 3, laser irradiation is used to melt the horizontal support rod, and the foundation pit dismantling is simulated, which has high efficiency and little disturbance to the surrounding soil. The camera 5 is used to shoot the inside of the model box to observe the dismantling of the support.

[0015] In this embodiment, the left end of the horizontal support rod 3 is pressed into the limiting groove, and the right end is locked on the ground-connected wall model 2 by a nut 8. The limiting groove is arranged on the inner side of the left side wall of the model box 1.

[0016] During installation, first fill the soil sample to the bottom of the foundation pit model, install and fix the ground-connected wall model 2 in the model box 1, and then insert the left end of the horizontal support rod 3 into the through hole on the ground-connected wall model from the outside of the foundation pit until it is pressed into the limiting groove on the ground-connected wall model, and then lock the right end on the ground-connected wall model 2 with a nut 8. Then, fill the remaining space in the model box with the test soil sample to ensure that the soil sample is filled densely and the foundation pit model is set at the predetermined position.

[0017] During the test, the model box is hoisted onto the centrifuge and the centrifuge is started. When the test soil sample is consolidated to a certain degree, the laser emission device is started to irradiate the horizontal support rods in sequence according to the test design plan until the support rods are melted and cut, the support fails, and the strain gauge data is read; the support removal situation is observed by video.

[0018] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the scope of protection of the present invention.

Claims

1. A centrifuge test device for simulating foundation pit support removal by laser irradiation, characterized in that: Including model box, The upper part of the model box is open, a test soil sample is arranged in the model box, a ground-connected wall model is pre-buried in the test soil sample, a row of strain gauges arranged in sequence from top to bottom are respectively arranged at the same position on both sides of the ground-connected wall model, the ground-connected wall model extends along the entire inner opening width of the model box, and the bottom is suspended above the bottom plate of the model box, a foundation pit model is formed between the ground-connected wall model and the left side wall, front side wall and rear side wall of the model box, and the bottom of the foundation pit model is formed by the test soil sample, A horizontal support rod made of aluminum alloy is provided between the ground-connected wall model and the left side wall of the model box. A laser emitting device and a camera are installed on the top of the model box, and the emitting direction of the laser emitting device is perpendicular to the horizontal supporting rod.

2. The centrifuge test device for simulating foundation pit support removal by laser irradiation according to claim 1, characterized in that: The left end of the horizontal support rod is pressed into the limiting groove, and the right end is locked on the ground-connected wall model by a nut. The limiting groove is arranged on the inner side of the left side wall of the model box.

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